LONTalk as a Standard Protocol For Underwater Sensor Platforms

Proceedings IEEE, Oceans 97, Halifax, Oct. 1997 IEEE CD-ROM 0-7803-4111-

LptO (PG0027) is required for lipid A 1-phosphatase activity in Porphyromonas gingivalis W50

ABSTRACT Porphyromonas gingivalis produces outer membrane vesicles (OMVs) rich in virulence factors, including cysteine proteases and A-LPS, one of the two lipopolysaccharides (LPSs) produced by this organism. Previous studies had suggested that A-LPS and PG0027, an outer membrane (OM) protein, may be involved in OMV formation. Their roles in this process were examined by using W50 parent and the Δ PG0027 mutant strains. Inactivation of PG0027 caused a reduction in the yield of OMVs. Lipid A from cells and OMVs of P. gingivalis W50 and the Δ PG0027 mutant strains were analyzed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Lipid A from W50 cells contained bis-P-pentaacyl, mono-P-pentaacyl, mono-P-tetraacyl, non-P-pentaacyl, and non-P-tetraacyl species, whereas lipid A from Δ PG0027 mutant cells contained only phosphorylated species; nonphosphorylated species were absent. MALDI-TOF/TOF tandem MS of mono-P-pentaacyl ( m / z 1,688) and mono-P-tetraacyl ( m / z 1,448) lipid A from Δ PG0027 showed that both contained lipid A 1-phosphate, suggesting that the Δ PG0027 mutant strain lacked lipid A 1-phosphatase activity. The total phosphatase activities in the W50 and the Δ PG0027 mutant strains were similar, whereas the phosphatase activity in the periplasm of the Δ PG0027 mutant was lower than that in W50, supporting a role for PG0027 in lipid A dephosphorylation. W50 OMVs were enriched in A-LPS, and its lipid A did not contain nonphosphorylated species, whereas lipid A from the Δ PG0027 mutant (OMVs and cells) contained similar species. Thus, OMVs in P. gingivalis are apparently formed in regions of the OM enriched in A-LPS devoid of nonphosphorylated lipid A. Conversely, dephosphorylation of lipid A through a PG0027-dependent process is required for optimal formation of OMVs. Hence, the relative proportions of nonphosphorylated and phosphorylated lipid A appear to be crucial for OMV formation in this organism. IMPORTANCE Gram-negative bacteria produce outer membrane vesicles (OMVs) by “blebbing” of the outer membrane (OM). OMVs can be used offensively as delivery systems for virulence factors and defensively to aid in the colonization of a host and in the survival of the bacterium in hostile environments. Earlier studies using the oral anaerobe Porphyromonas gingivalis as a model organism to study the mechanism of OMV formation suggested that the OM protein PG0027 and one of the two lipopolysaccharides (LPSs) synthesized by this organism, namely, A-LPS, played important roles in OMV formation. We suggest a novel mechanism of OMV formation in P. gingivalis involving dephosphorylation of lipid A of A-LPS controlled/regulated by PG0027, which causes destabilization of the OM, resulting in blebbing and generation of OMVs. </jats:p

Critical Care Cycling Study (CYCLIST) trial protocol: a randomised controlled trial of usual care plus additional in-bed cycling sessions versus usual care in the critically ill

Introduction In-bed cycling with patients with critical illness has been shown to be safe and feasible, and improves physical function outcomes at hospital discharge. The effects of early in-bed cycling on reducing the rate of skeletal muscle atrophy, and associations with physical and cognitive function are unknown. Methods and analysis A single-centre randomised controlled trial in a mixed medical-surgical intensive care unit (ICU) will be conducted. Adult patients (n=68) who are expected to be mechanically ventilated for more than 48 hours and remain in ICU for a further 48 hours from recruitment will be randomly allocated into either (1) a usual care group or (2) a group that receives usual care and additional in-bed cycling sessions. The primary outcome is change in rectus femoris cross-sectional area at day 10 in comparison to baseline measured by blinded assessors. Secondary outcome measures include muscle strength, incidence of ICU-acquired weakness, handgrip strength, time to achieve functional milestones (sitting out of bed, walking), Functional Status Score in ICU, ICU Mobility Scale, 6 min walk test 1week postICU discharge, incidence of delirium and quality of life (EuroQol Five Dimensions questionnaire Five Levels scale). Quality of life assessments will be conducted post-ICU admission at day 10, 3 and 6 months after acute hospital discharge. Participants in the intervention group will complete an acceptability of intervention questionnaire. Ethics and dissemination Appropriate ethical approval from Metro South Health Human Research Ethics Committee has been attained. Results will be published in peer-reviewed publications and presented at scientific conferences to assist planning of future multicentre randomised controlled trials (if indicated) that will test in-bed cycling as an intervention to improve the physical, cognitive and health-related quality of life outcomes of patients with critical illness

In-bed Cycling with Critically Ill Patients: Practical Lessons From a Randomised Trial

Introduction: In-bed cycling for critically ill patients is a rehabilitative exercise that may help improve patients’ functional status at hospital discharge. In-bed cycling is not currently implemented early during a patients’ critical illness. Objectives: To identify if early in-bed cycling could be safely implemented following a patients’ admission to ICU and to identify the barriers and facilitators to implementation of in-bed cycling within ICU. Methods: A randomised controlled trial comparing usual care physio-therapy with additional in-bed cycling within a tertiary mixed medical, surgical, trauma ICU was conducted. Number of sessions of in-bed cycling planned, conducted, distance and duration cycled, haemodynamic parameters and occurrence of pre-defined adverse events were recorded. A diary of intervention implementation processes and outcomes was kept to identify barriers and facilitators to implementation of in-bed cycling. Results: Thirty-seven participants completed 276 of 304 (90.8%) planned in-bed cycling interventions. Participants completed a median (IQR) of 6 (4,8) in-bed cycling sessions. Participants commenced in-bed cycling a median (IQR) of 2.3 (1.8,3.1) days following ICU admission. Participants cycled a mean (SD) 27.7 (5.2) minutes per session and mean (SD) 3.23km (1.63km) per session and maintained haemodynamic stability. Two minor adverse events (0.7% of sessions) occurred that required clinician intervention (increased respiratory rate and oxygen desaturation). These events required adjustment to ventilator settings without any long-term consequences. The main barriers to the implementation of in-bed cycling sessions were patient fatigue (n = 9), delirium (n = 5) and haemodynamic instability (n = 4). Timing of initiation of the intervention following morning chest x-ray round with independent implementation by a physiotherapist were identified as the main facilitators to the in-bed cycling intervention. Conclusions: In-bed cycling commencing within 2 to 3 days of a patients’ ICU admission was both safe and feasible. Adverse events were rare and the main barrier to implementation of in-bed cycling sessions was patient fatigue.<br/

Identification of hydroxyapatite spherules provides new insight into subretinal pigment epithelial deposit formation in the aging eye.

Accumulation of protein- and lipid-containing deposits external to the retinal pigment epithelium (RPE) is common in the aging eye, and has long been viewed as the hallmark of age-related macular degeneration (AMD). The cause for the accumulation and retention of molecules in the sub-RPE space, however, remains an enigma. Here, we present fluorescence microscopy and X-ray diffraction evidence for the formation of small (0.5-20 μm in diameter), hollow, hydroxyapatite (HAP) spherules in Bruch's membrane in human eyes. These spherules are distinct in form, placement, and staining from the well-known calcification of the elastin layer of the aging Bruch's membrane. Secondary ion mass spectrometry (SIMS) imaging confirmed the presence of calcium phosphate in the spherules and identified cholesterol enrichment in their core. Using HAP-selective fluorescent dyes, we show that all types of sub-RPE deposits in the macula, as well as in the periphery, contain numerous HAP spherules. Immunohistochemical labeling for proteins characteristic of sub-RPE deposits, such as complement factor H, vitronectin, and amyloid beta, revealed that HAP spherules were coated with these proteins. HAP spherules were also found outside the sub-RPE deposits, ready to bind proteins at the RPE/choroid interface. Based on these results, we propose a novel mechanism for the growth, and possibly even the formation, of sub-RPE deposits, namely, that the deposit growth and formation begin with the deposition of insoluble HAP shells around naturally occurring, cholesterol-containing extracellular lipid droplets at the RPE/choroid interface; proteins and lipids then attach to these shells, initiating or supporting the growth of sub-RPE deposits

Valid and reliable assessment of wellness among adolescents: Do you know what you’re measuring?

Measuring wellness among adolescents is an emerging trend among professionals and researchers endeavouring to influence youth as they establish lifestyle patterns in this critical period of life. This discussion highlights instruments used to measure adolescents’ wellness, and considers the empirical data supporting the validity and reliability of those instruments. In summary, adolescents’ wellness is an important indicator of future health and lifestyle habits. There are a number of tools available to measure wellness, each with its own focus, depending on the definition or model from which it was developed. This might cause debate regarding the appropriateness of some instruments for evaluating wellness. The majority of wellness evaluation approaches used with adolescent populations have less than ideal validation. A ‘gold standard’ definition could lead to the standardisation of a theoretical model against which wellness instruments could be validated. The absence of peer-reviewed studies reporting psychometric testing for wellness evaluation instruments used with adolescents is of concern given their growing popularity and highlights a priority area for future research in this field

Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration

[EN] One of the most interesting innovations in the CCS (Carbon Capture and Storage) field is the use of MCFCs as carbon dioxide concentrators, feeding their cathode side (or air side) with the exhaust gas of a traditional power plant. The feasibility of this kind of application depends on the resistance of the MCFC to air-side contaminants, with particular attention to SO2. The aim of this work is to investigate the effects of poisoning when sulphur dioxide is added to the cathodic stream in various concentrations and in different operating conditions. This study was carried out operating single cells (80 cm(2)) with a cathodic feeding composition simulating typical flue gas conditions, i.e. N-2, H2O, O-2 and CO2 in 73:9:12:6 mol ratio as reference mixture. On the anodic side a base composition was chosen with H-2, CO2 and H2O in 64:16:20 mol ratio. Starting from these reference mixtures, the effect of single species on cell poisoning was experimentally investigated considering, as main parameters chosen for the sensitivity analysis, SO2 (0-24 ppm) and CO2 (4-12%) content in the cathodic feeding mixture, H-2 (40-64%) content in the anodic stream as well as the operating temperature (620-680 degrees C). Results showed that degradation caused by SO2 poisoning is strongly affected by the operating conditions. Data gathered during this experimental campaign will be used in a future work to model the poisoning mechanisms through the definition of MCFC electrochemical kinetics which take into account the SO2 effects. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.The work was partly supported by H2FC European Infrastructure Project (Integrating European Infrastructure to support science and development of Hydrogen and Fuel Cell Technologies towards European Strategy for Sustain-able Competitive and Secure Energy) Theme [INFRA-2011-1.1.16.], Grant agreement 284522.Della Pietra, M.; Discepoli, G.; Bosio, B.; Mcphail, S.; Barelli, L.; Bidini, G.; Ribes-Greus, A. (2016). Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration. International Journal of Hydrogen Energy. 41(41):18822-18836. https://doi.org/10.1016/j.ijhydene.2016.05.147S1882218836414

Structural changes and conductance thresholds in metal-free intrinsic SiOx resistive random access memory

We present an investigation of structural changes in silicon-rich silicon oxide metal-insulator-metal resistive RAM devices. The observed unipolar switching, which is intrinsic to the bulk oxide material and does not involve movement of metal ions, correlates with changes in the structure of the oxide. We use atomic force microscopy, conductive atomic force microscopy, x-ray photoelectron spectroscopy, and secondary ion mass spectroscopy to examine the structural changes occurring as a result of switching. We confirm that protrusions formed at the surface of samples during switching are bubbles, which are likely to be related to the outdiffusion of oxygen. This supports existing models for valence-change based resistive switching in oxides. In addition, we describe parallel linear and nonlinear conduction pathways and suggest that the conductance quantum, G0, is a natural boundary between the high and low resistance states of our devices